president obama will go head-to- head with mitt romney and the stakes are high for both men. >> romney has had a rough few weeks with gaffes. obama is desperate to open up a clear lead with over a month until election day. >> and have been both preparing for the debate in denver. >> the first presidential debate is causing havoc, highways. security is tight in denver. the state of colorado is a tossup between the candidates, making this crucial period every di tella said, even the room temperature and lighting. president obama leads republican challenger mitt romney by three percentage points in national polls. romney is within striking distance. both men have been preparing for weeks. president obama's advisers have been telling him not to be professorial. do not speak for too long. for mitt romney, they're saying do not commit a gaffe. try to stay on message. that is why he has practiced. >> mitt romney arrived in denver early, visiting a mexican fast- food restaurant. this and a 7% of hispanic voters in the u.s. support obama. the president spent three days preparing in nevada where